Process of decolorizing tannic extracts.



40 and a very eili'cient decolorizatlon will there- ,UNITE srj ensLORENZO DUEOUR, OF GENOA, ITALY.

onto .1

PROCESS OF DECOLORIZIN TANNIC EXTRACT$.

To all whom it may concern:

Be it'knou-n that I, LORENZO DUFoL'R,

subject of the King of Italy, residing at Genoa, Italy,- have inventedcertain new and useful Improvements in Processes of DecolorningFannie-Extracts, of \z'hieh the following is a specification.

' acid. an! the m cntiur colorization.

ample that a mixture of Havingfolzserved the singular reducing anddecolorizmg proprrtics'of a n'nxture of hypoph'osphite and a sulfite inacid solution, ore mixture of liypoplmsphorir and phosphorlc .aeld-v 1thsulturous and I use this property in connection \-.ith the decolo'rization of tannin extracts.

I have further ol'servcd that hy the addition of formaldehyde to thesaid mixture its reducing; properties and stability are muteriallyincreased, and that 'a certain degree of'heating is necessary to obtaincomplete dehyde has given the most satisfactory results,

.the degree of. heating heing variahlo according to the quality ofextract to he decolorii ez l ill give hereunder t o practical examples:

I I. I take TCDO kg. of extract of quehracho at 25 Be. heated up tofluid condition and add thereto 3 lw. ol' sodic hypophosnliite and '15kg: of sodir nisulfite dissohed in water, thoroughly mixing"togethor thevhole: I.

then .add 5 kg. of-I ulfurir acid at 409 B6,

' and after having been mixed thoroughlythe whole isheutod to 6(l"-10for. some hours,

hy-heobtained. i I

2. To '1000 kg. of extract "of mangrove bark at 25 B.-l add 5 kg. ofsod'ie hyiio phosphite'and 20 kg. of sodiebisulfite issolved in alittle'water, thoroughly ll-llxlllg together the whole. I then add 7 kg.sulfuric acid at 4091313.andfikg.'ol'formalinofstztndard strength I lwhcn thoroughly mixed I Specification of Letters Patent.

Application filed July 25.1906. Serial No; 327.690.

Permanent. 11, 1908.

and obtain a very remarkable decolorization thereby.

1n analogous manner as the above two ex tracts all the -other extractsto be used for tanning may be treated, only varying the quantity ofdecolorant and the degree of heating according tothe particularproperties oi the extract to be decolorized.

Having now fully described my said in' vention and the manner in whichthe same is to he performed,- What I claim and desire to secure byLetters Patent of the. United Statesis:

lfA process (inrcatirig tannic extracts which consists in adding theretoa reducing agent con'iprising in separate combinations the suliurousacid radical and the phosphorous acid radical and adding thereto an acidcapable of displacing the said radicals, sub

stantially as described.

2. A rocess of treating tannic extrects which consists-in adding theretoa redticing agent compr sing in separate combinations 1 the sulfurousacid rzidical and the phosphor ous acid radical, adding thereto an acidcaiable of displacingjthe'seld .radlcais and heat.

mgthe mixture, substantially as described.

3; A process oftrcatingtannic extracts which consists in adding theretoa reducing agent comprisrnggm se arate combinations the sulfurous acidraiical and the phbs-k.

lp'horous acid radical, said reducing agent )eing associated withformaldehyde and ,add ing thereto an acid capableof dlsplacingthe saidradicals.

4. A process of treating tannic extracts which consistsin adding theretoa'reducing agent conrprisingin se arate combinations the sulfurous acidra ical and the phosihorousn'cid radical, said reducing agent lieingassociated with formaldehyde, addin thereto an arid capable ofdisplacing the sai "radicalsand heating the mixture, substan-.

tially as described;

in testimony whereof I have affixed my signature in presence of twowitnesses.

' K LURENZO' DUFOUR. W i tnesscs lomiiso idiissA,

Gunners lt'lAccAGUI.

